PROJECT SUMMARY In this Phase II SBIR application, we will build on progress in Phase I to commercialize qF-ProbeTM for quantitative intraoperative measurement of ALA-induced PpIX concentration (CPpIX) during open-cranial brain tumor resection. Specifically, in Phase I, we developed a disposable probe design and prototypes that are comparable in performance to our established reusable clinical-research probes, and created an instrument design that meets clinical-user specifications, maintains accuracy/repeatability equivalent to our existing high- performance research units and has additional flexibility for adaptation to other fluorophores. The qF-ProbeTM concept arose as part of NIH-funding (R01 NS052274-09; PI: Roberts) in fluorescence-guided surgery involving biomedical engineering/optics and neurosurgical research teams at Dartmouth and Toronto. InSight Surgical Technologies LLC was then founded by the senior members of this collaboration who bring substantial domain expertise. Commercialization is particularly timely, since (i) ALA-PpIX fluorescence-guided surgery has been FDA approved for high-grade glioma, (ii) substantial corporate moves have occurred in fluorescence-guided surgery indicating a significant global market (e.g., Stryker purchase of NOVADAC for ~$700M in 2017, and incorporation of fluorescence detection by market leader in surgical robotics, Intuitive Surgical.), (iii) interest from other MedTech companies (e.g., Medtronic, Zeiss) is high, and (iv) the extensive clinical results demonstrate compelling advantages of quantitative CPpIX over qualitative and subjective visual fluorescence imaging. Indeed, our research-grade instrument and reusable probes have been deployed in >200 brain tumor patients at 2 major US centers and demonstrate that levels of PpIX fluorescence not visible or detectable with commercially-available systems (e.g., Zeiss Blue 400) can be quantified. Doing so results in significantly greater sensitivity and specificity for detection of residual tumor at end of white-light resection, enabling more complete tumor removal, including in low-grade as well as high-grade tumors. Additionally, qF- ProbeTM can be modified to detect (i) other fluorophores, (ii) tumor at depth below the resection bed and in the presence of a thin film of blood, and (iii) multiple fluorophores in the same case. These capabilities will be implemented in future products. InSight?s business plan positions qF-ProbeTM as the first product to market, establishing the clinical value of fluorophore quantification during surgery. In Phase II, we will finalize the probe and instrument designs under full QMS design-control and in compliance with industry regulations, produce up to 5 fully functional qF-ProbeTM systems, validate the final design through clinical usability and survey data, and apply to FDA for 510k regulatory clearance.